strange request

slayer200230

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Sep 8, 2017
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i have been playing around with building a power wall, ive got 18650's, charge controller, 2 230w solar panels, all fused and hooked up and working. problem is i live in an apartment and for the near future can not install the panels on the roof. (ive gotten permission, just need the man power and the roof is not easily accessible) so ive been playing around with mostly no charge from the 24v panels from the little light threw my window. i would like to be able to do run time test on the packs i have wired up. but i cant wait days to get a 80% charge. i thought of buying a 24v 5a dc power supply, and using it as a solar panel. kinda trick the charger to use it instead. is that possible? this would allow me to do longer test as if my panel was giving me the 8a that its capable of.


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Its possible as long as you get a proper CC/CV supply. they have no issues with running as such a source.
And if you dont have a powersupply since before i really like this design:

Link to a search on Ebay for the type I like:
https://goo.gl/nznnNZ

They are good because you can set output to simmulate the solar panel. Just need input source from AC and you are good to go.
 
i ended up buying one of these
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but it doesnt do anything. if i hook it up it just acts like nothing is hooked up
 
Most likely because either the power supply shuts down due to overload, if it has OCP, or the controller shuts down because the power supply can't keep the voltage up under the load the controller puts on the power supply. That is why you need a power supply where you can limit the current. The 5 amps on the one you have is just its rated maximum, it isn't limited at 5 amps. Unless it has OCP, but if that triggers, then the power supply is off which obviously doesn't help :)
 
Does it only have 2 wires come out of it? If not, one may be a load indicator. Or, you may need to put a resistor between pos/neg to get it to turn on. Not sure of the ohm-age, though
 
when i hooked it up and tested for voltage at the pins, i got 24v. but no sign of change with the charger. tested to make sure charger was ok this morning and still accepted solar panels.
im using Sunix 20A 12V/24V Solar Charge Controller Charge Regulator Intelligent , USB Port Display Overload Protection Temperature Compensation.


and yes only 2 wires
 
Have you tried putting a light on it to see if it's working? A regular AC bulb would work, just glow red instead of whitish.
 
if you are only interested in testing if your packs will take a charge?
looks like you have multiple 4 s battery pack.
Why not charge up the battery packs directly with your 24 volt dc power supply? testing voltage at the battery pack as you charge the battery.
you seem to have a 7s 4p setup which can take XX.X volts(correct voltage 25.9)
proceed at your own risk method not tested (bull in china shop method)
 
im wanting to run it threw the charge controller for protection, i have a bunch more battery packs to connect in, 7s 80p is what im going for to start with, i have enough to do 7p 16s, and i want to run test runs, how long does the fan run on battery, how long does it take to recharge with 5a. ect. trying to scale the numbers up since if i understand my panel numbers. ill have 16a max and my charge controller is a max of 20a. but for some reason the charge controller wont see the power supply as a panel
 
just realized I over stated the 7 s voltage should be 25.9 volts
I see what you are trying to do now. please disregard my previous post.
later floyd
 
can anyone say for sure that the DPS5015 will work? i dont want to waste 50$ is there a way to test whats causing mine to not work?
 
100% for sure? No, probably not. But it will likely work. It won't though if the problem is somewhere else in your system. I have just realized you have 24V panels. They probably can't replaced by a 24V power supply anyway, the voltage is too low. 24V panels usually have something like ~38Voc and ~30Vmp, don't they? You should take a look at the specs of your panels.

Also remember that the DPS5015 is a buck converter, its output will alway the less than the input. If you want to put out 30V you will have to put in more than 30V into the DPS5015. Ruideng, the company who makes these, says the ratio should be at least 1,1 so you need at least a 33V input to get your 30V output. With current limited to ~8A you need a 300W power supply capable of producing at least 33V. You could try to use your 24V power supply first to power the DPS5015 and then feed your solar controller with a really low voltage of ~22V but I can only guess if that would work.
Does your solar controller support 12V as well? If so, you could connect a ~12V battery and feed it with ~16/17V (Vmp for a 12V panel) from the DPS5015 which in turn can then be powered by the 24V power supply you already have. It won't be like your final setup but at least you could start and try something.
 
it does support 12v, only thing i noticed tho was that at 12v using a 4s setup, they dont last long. and at 3s i have to run the batteries at ~4v that is why i ended up choosing the 24v setup, i do have a step-down on my output to bring it to 12v, so i can use my cheap car inverter instead of buying a 200$+ inverter, and they seem to last a lot longer. so im thinking i could just buy a 30v charger or should i go with something around 35v like http://www.ebay.com/itm/Adjustable-...846939?hash=item1ecc13785b:g:NOkAAOSwjJRZdwVo


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Yes, the voltage ranges aren't ideal, but at least you could start with something. You've done the right thing and went for 24V, but for testing purposes 12V will work as well and you only need the DPS5015. For 24V you need something like the powersupply you've linked and the DPS5015 (or some of the smaller ones like DPS5005, you can't use all its power anyway), watch for its total power though. It's a rather small one.
 
Hey Just a thought I do know that most are not current limited. so u have a 20amp controller over current your power-supply. because your charge controller trys to pull max a solar panel can put out. well a psu will just put out till it dies unless its current limited. you can buy a cheap cc-cv psu on amazon for like 10 bucks. that is what i use anyway.
 
I've been charging my batteries with a 7201a boost converter and using a laptop/generic brick power supply. it's not a permanent method but it works well as you can limit the current.
 
slayer200230 said:
would you be able to link to one of the 10ish cc-cv psu? all im finding is 300$ psu

You can find them on Amazon, eBay, Gearbest, Banggood...Look around depending on where you want to shop. They are just smaller and therefore cheaper variations of the DPS5015 you've already found. What CaptFullbird suggested is the same what we've already established and what you we're going to try anyway.
 
oh i see, was thinking there was an all in one solution for 10$ , i follow now. sorry for the confusion
 
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